نشریه التیام
سال دهم شماره 1 (بهار و تابستان 1402)

Cartilage is a strong, flexible connective tissue that protects joints and bones. It acts as a shock absorber throughout body. Cartilage is divided into different types based on the type of fibers in the underlying tissue as well as the percentage of their composition, each has different functional characteristics. Hyaline cartilage is the most common and abundant type of cartilage rich in type ΙΙ of collagen fibers and proteoglycan. Elastic cartilage has more flexibility and in the matrix of this cartilage, in addition to the type ΙΙ of collagen fibers, a large amount of elastic fibers is also present. In fact, the presence of these elastic fibers is a factor in the ability of this type of cartilage to change shape and return to its original state. The fibrocartilage is the strongest type of cartilage. The characteristic feature of this type of cartilage is high weight bearing. Fibrocartilage contains collagen fibers scattered between layers of the matrix. The restorative strength of cartilage tissue is very limited and the repair of this tissue after injury is always accompanied by challenges and problems. Articular cartilage damage is considered as one of the most important challenges of orthopedic surgeons. Today, different methods are used to treat the articular cartilage defect, however, in none of the methods complete restoration and restoration of tissue integrity of articular cartilage is achieved. Surgical procedures are divided into two categories, reparative and restorative surgery. The purpose of this article is to review the structure of cartilage and the methods of articular cartilage healing.

Tendons are soft connective tissues composed of parallel collagen fibers embedded in an extracellular matrix. This organized structure allows the tendons to bear and transfer large forces between the muscle and the bone. Tendons contain 86% collagen, 1-5% proteoglycan ,and 2% elastin, which are calculated as dry weight, and water is responsible for 60-80% of the wet weight of the whole tendon. Tendon healing can be generally divided into 3 phases; the repair, inflammation, and remodeling phases. Although the tensile strength of the healed tendon improves over time, it does not reach the level of uninjured tissue.

Fracture repair involves proliferation and differentiation of multiple tissue types in a sequence followed by regeneration. All of these processes may be affected by medications. Some drugs can affect the proliferation of primary callus tissue, others can affect the differentiation of chondrocytes or osteoblasts, formation of capillaries, sensitivity to mechanical input, etc. Therefore, the subject of drugs and fracture repair not only includes pharmacology and orthopedics, but also includes a wide scope. Repair steps after bone damage include: stage 1: (swelling stage), stage 2: (primary bone repair): over the next 4 to 21 days, a callus is formed around the broken bone. In this stage, a substance called collagen gradually replaces the blood clot. Step 3: (secondary bone repair) approximately two weeks after the fracture, cells called osteoblasts start working. These cells cause new bone to fuse and provide minerals needed for bone strength. Step 4: (reconstruction step): in this stage, cells called osteoclasts make the needed changes and adjustments. These cells break down any extra bone that is formed during this healing phase to return the bone shape to its normal status. In current veterinary and also human orthopedics, bone grafts are used for stimulation of fractures healing, accelerate joint fusion and repair of bone defects. Native grafted bone in addition to healing stimulator substances, contains cells that do not stimulate immune reactions and do not transmit infectious diseases. Currently, due to the problems of autologous bone grafting, the desire to use non-autologous bone grafts such as allograft and xenograft has increased. Kinetic hydroxyapatite, tricalcium phosphate and their both combination are among the common materials for bone grafting. Hydroxyapatite works as a scaffold for the growth of bone-forming cells; tarantula cubensis is an extract that is widely used in the treatment of tumors, smallpox, septicemia and toxemic diseases. Also, other materials that are used as substitutes, after being implanted at the site of bone lesions, induce the differentiation of undifferentiated mesenchymal cells present at the site of the lesion into chondrocytes or immature bone cells, and finally, the defects are successfully repaired.

ameness is a common problem in small animal medicine. Since animals, especially dogs, bear most of their weight on their front legs, it seems necessary to examine the fore limb. Diagnosis and treatment of fore limb lameness are often difficult. Diagnosis of the lesion is difficult because patients usually do not show obvious pain on palpation. Investigation of the cause of lameness and the anatomical location of the lesion depends on the age, breed, and lifestyle of the animal. Therefore, a systematic orthopedic examination of the extremity is critical to ensure that all structures are assessed and no part is overlooked. An orthopedic examination includes not only a clinical examination of the patient but also an anamnesis, gait observation, stride analysis, and evaluation. First, a history of lameness, diagnosis, previous treatment, and its effectiveness, presence of other systemic conditions, and diet should be evaluated. Assessing a patient's gait on flat and sloping surfaces at different speeds can help understand which limb is lame. Studying and analyzing animal movements is considered a very important step in detecting organ damage and abnormalities. Abnormal gait that may be caused by nerve or musculoskeletal damage is therefore called lameness. It is caused by hereditary, congenital, developmental disorders, trauma, and infection of this organ. Finally, an orthopedic clinical examination of the animal is performed. The appearance of pain during the examination indicates the localization of the lesion since an orthopedic examination of the organ does not cause pain in healthy animals. First, the normal, seemingly healthy side is checked so that the animal is calm and so that individual responses to specific tests can be judged. Therefore, this article describes a method for systematic orthopedic examination of the fore limb.

Lameness is a common complaint in small animal medicine. Orthopedic examination is performed by visual and manual assessment of the patient. In most cases, the affected extremity is identified, but the exact origin of that extremity remains obscure and sometimes difficult. Orthopedic examination plays an important role in determining the location of lameness, diagnosing its cause, and finding appropriate treatment. Early diagnosis of musculoskeletal problems is very important to apply appropriate treatment and preventive measures in the early stages of disease progression. Patients presenting with symptoms of musculoskeletal abnormalities should undergo a complete orthopedic examination. A systematic approach to orthopedic examination is important to assess all structures and ensure that no part is missed. The purpose of orthopedic examination is to assess the presence or absence of the disease in the patient and determine the causes of its occurrence. The orthopedic examination includes history taking, walking observation, step analysis and evaluation, and clinical examination of the patient. A history of lameness, previous diagnoses and treatments and their effects, the presence of other systemic diseases, and diet should be documented before the initiation of clinical examination. The time of onset of lameness, possible causes, and the timing of progression also help in a better diagnosis. It is very important to observe the patient walking from different directions at different speeds. Observing the patient going up and down stairs and ramps may also help. Understanding movement and gait is important for diagnosing many musculoskeletal and neurological problems. Gait analysis should be performed before any orthopedic or neurological examination. Gait analysis can help further clarify which limb is affected. Finally, an orthopedic clinical examination of the animal is performed. This article describes methods for clinical examination of the hind limb.

External fixation by means of coaptation means using casts, splints, bandages, and slings to immobilize the injured limb. These methods if used properly approximate the shape of the limb on which they are applied and provide stable fixation of bone fragments without the need for surgical implants at the fracture site. External fixation of orthopedic injuries in veterinary medicine has significant advantages over open fixation and internal fixation. In most cases, the soft tissue and vascular damages, the risk of infection, and the cost of its use can be much lower than surgical intervention. Careful case selection is required to achieve successful treatment of fractures with external coaptation. Temporary fixation methods are usually used to prevent edema, relieve pain, reduce subsequent soft tissue damage, protect the wound from further contamination, prevent the conversion of closed fractures to open fractures, and stabilize the fractured particles in acutely injured animals. Various types of External coaptations are available in veterinary practice to provide the best external fixation of injuries. Therefore, it is essential for the practitioners in this field to have sufficient familiarity with different methods and their uses. As a general rule, external coaptation is an acceptable mode of fracture repair for animals that are younger than 1 year of age, because they heal faster. External coaptation best neutralizes flexion forces on distal fractures and requires stabilization of the joint above and below the fractured site. Therefore, coaptation has the disadvantage of prolonged immobilization of the limb, which can cause severe atrophy from "disuse atrophy" and possible "fracture disease".

An external skeletal fixator is an orthopedic method for treating open or closed fractures of long tubular bones, joint stiffness, bone lengthening, and congenital malformations. An external skeletal fixator is a device that is installed outside the organ and inserts pins into the fracture to fix it and adjust the position of the pin. They are connected to the frame and secured with bolts and nuts. Fixtures have changed significantly in appearance and biomechanics over time, but the principle and function remain the same. These fixtures consist of pins or thin stainless steel wires that penetrate the skin and reach the bone. This way the broken part is fixed in the right direction. Depending on the body geometry and shape, these external skeletal fixators are available in different types such as linear, circular, and hybrid fixators. The simplest and most common type of external skeletal fixator is the linear fixator. The use of an external fixator has several advantages over other fixation methods such as stabilization of the fracture at some distance from the injury site, no need for a cast, ease of patient movement, and minimal involvement of the joint. Premature loosening of the pin is the most common complication causing pain, inflammation, and discharge from the pin tract. Although these fixators are versatile and effective treatment models, they require careful maintenance during treatment. Before deciding to use an external fixator, the patient's and pet's owner's ability to comply with postoperative care instructions should be considered. This article reviews the types of external fixators, postoperative care, and their complications.

Bone fractures in dogs and cats are usually see and we concern with those in the clinic. Usually, fractures occur after a traumatic accident such as being hit by a car or falling from a height, some fractures occur following pathological bone weakening, which is seen with some neoplastic conditions such as osteosarcoma. The main goals of fracture stabilization; Immobilization of broken parts, quick repair of the damaged bone, return of primary mobility, full function and stability to weight bearing of the bruise limb. All internal and external fixation methods that allow significant intersegmental motion under weight bearing are considered flexible fixation. The best important point in the stabilization of fractures is that a possibility of repair, that is, the blood supply to the place is maintained and the fixation is not so tight that it leads to a delay in bone fusion. Open fixation and internal fixation have been used to restore bone anatomy and original mobility and to overcome the limitations encountered when treating fractures with skeletal traction or cast immobilization. The main goal of internal fixation is to achieve rapid and, if possible, full function of the affected limb with rapid rehabilitation of the patient. The selection of the internal fixation method is based on the classification of the fracture, break bone, synchronize injuries, open fracture, and of course the forces that are neutralized by the fixation method. Internal stabilization implants are made of stainless steel and include; There are intramedullary pins, orthopedic wire, plates and screws.

Orthopedic diseases of young animals affect the musculoskeletal system of juveniles, and most of these diseases can be traced to pathological processes (such as diseases, toxins, improper nutrition, trauma) during this period. These diseases related to bones and joints begin and develop during skeletal development after birth, in the first 26 weeks of life. This group of pathological conditions of young dogs and cats, including congenital and neonatal orthopedic diseases, includes diseases that occur in the prenatal period or in the first 3 to 4 weeks of life. During the growth period, the morphology of the joints develops, the bones also mature and reach their length and shape in an adult animal. Orthopedic diseases of young animals are deviations of these regular processes. These diseases are a common problem in dogs and cats, can be painful and are not easily noticeable. These diseases can affect the bones, cartilage and joints of young animals and cause lameness, stiffness and difficulty moving. Early diagnosis and treatment are very important for successful outcome in these diseases. Veterinary clinicians should be aware of the signs and symptoms of these diseases, including lameness, joint pain, swelling, and difficulty moving. Diagnostic tests such as radiography and blood tests can help make the diagnosis. According to the type of disease, the treatment options are different and can include drugs, surgery or other interventions and may even be incurable. Prevention is also important in reducing the risk of orthopedic diseases in young dogs and cats, by preventing the mating and sterilization of animals with genetic disorders, it is possible to prevent the next generation from getting genetic diseases. Nutrition, exercise and weight management can also contribute to healthy bone and body growth in young animals. Veterinary course checkups can also help identify potential problems at the right time and prompt interventions and treatment.

Patellar luxation is a common orthopedic problem in dogs. Both large and small breed dogs may be affected; the disease may be seen in cats as well. Medial luxation is more common than lateral luxation and is usually diagnosed in dogs of small breed. patellar luxation based on severity of occurred changes divided to 4 different grades. Patellar luxation is a congenital/developmental disorder, but it could be secondary to traumatic accident causing tearing or stretching of the joint capsule and fascia, leading to femoropatellar instability. Diagnosis is based on clinical evidence of patellar instability; however, diagnostic imaging is required to assess the amount of skeletal deformity and then the most appropriate method of treatment. Clinical signs of dogs with patellar luxation can vary from animal to animal and are only partially related to the degree of concomitant skeletal deformities. Lameness may be intermittent or continuous, and usually is a mild-to-moderate weight bearing lameness with occasional lifting of the limb. Concurrent rupture of the CrCL has been reported in a study in 41% of the stifle joints of dogs with medial patellar luxation. Surgical options include both soft tissue and osseous techniques, however, in most of the cases, a combination of more procedures is used to achieve the correction of the luxation. Complication rate is generally low and the most common complications include reluxation and implant-associated complications. Prognosis is generally favorable, with most of the dogs returning to normal limb function. This article describes patellar luxation features in dogs, including clinical presentation, diagnosis, and treatment options available

Atopic dermatitis is a common pruritic and inflammatory dermatosis with genetic background and specific clinical manifestations. The present study was carried out with the aim of improving the knowledge and integration of the treatment protocols of veterinarians in Iran. The current research is a review based on the based on the task force for the treatment of canine atopic dermatitis (International Committee of Allergic Diseases of Animals) and a summary of the author's researches in the field of dermatology. The treatment of acute flares of canine atopic dermatitis should involve three parts; 1- To search for and then to eliminate the causes and/or aggravating allergens such as plant pollen allergens, house dust mites (dermatophagoides), pyoderma and/or Malassezia dermatitis. 2- Antimicrobial treatment and improvement of skin and hair health, such as bathing with mild shampoos. 3- To control pruritus and skin lesions with interventions that include topical and oral glucocorticoids, oral Oclacitinib, and injectable recombinant interferons. 4- Immunotherapy using specific allergens and prophylactic administration of topical glucocorticoids are the only interventions that may prevent or delay the recurrence of dermatitis. There is no conclusive evidence to prove the efficacy of: 1- Antihistamines in the treatment of atopic dermatitis in dogs 2- Administration of oral essential fatty acids due to the long time required for any effective effect. The treatment of acute flares of atopic dermatitis is multifaceted, and in order to achieve the optimal therapeutic effect, therapeutic interventions must be combined. Before designing a treatment plan, it is necessary to consider the quality of life of dogs and their owners, as well as the preference of the owner's opinion.